In 2010, Russia baked through its most intense heat wave in recorded history, one that killed over 55,000 people. At the same time, intense rains deluged Pakistan, bringing that nation its worst natural disaster in its history. The following year, it was the United States' turn for extreme heat, as the nation sweltered through its third hottest summer on record, and Oklahoma suffered the hottest month any U.S. state has ever recorded. The U.S. summer of 2012 was even more extreme. Only the Dust Bowl summer of 1936 was hotter, and drought conditions were the most extensive since the 1930s. All of these events--and many more unusually extreme summer months in recent decades--had a common feature, said scientists at the Potsdam Institute for Climate Impact Research (PIK) in Germany, in a research paper published in March 2013 in Proceedings of the National Academy of Sciences. According to the authors, "each time one of these extremes struck, a strong wave train had developed in the atmosphere, circling the globe in mid-latitudes. These so-called planetary waves are well-known and a normal part of atmospheric flow. What is not normal is that the usually moving waves ground to a halt and were greatly amplified during the extreme events. Looking into the physics behind this, we found it is due to a resonance phenomenon. Under special conditions, the atmosphere can start to resonate like a bell. The wind patterns form a regular wave train, with six, seven or eight peaks and troughs going once around the globe". Using a complex theoretical mathematical description of the atmosphere and 32 years of historical weather data, the scientists showed that human-caused global warming might be responsible for this resonance phenomenon, which became twice as common during 2001 - 2012 compared to the previous 22 years.

Figure 1. Drought-damaged corn in a field near Nickerson, Nebraska, Aug. 16, 2012. The great U.S. drought of 2012 was the most extensive U.S. drought since the 1930s Dust Bowl. Damage from the 2012 drought is at least $35 billion, and probably much higher. The associated heat wave killed 123 people, and brought the U.S. its second hottest summer on record. (AP Photo/Nati Harnik)

Figure 2. Business was slow at the Lake Conroe, Texas jet ski rental in 2011, thanks to the great Texas drought and heat wave of 2011. Texas endured its driest 1-year period on record in 2011, and had the hottest summer ever recorded by a U.S. state. July 2011 in Oklahoma was the hottest month any U.S. state has ever recorded, and the contiguous U.S. had its third hottest summer on record. The total direct losses to crops, livestock and timber from the drought, heat wave, and record fires of the summer of 2011 are estimated at $12 billion, with a death toll of 95. Image credit: wunderphotographer BEENE.

Figure 3. Tourists wear protective face masks as they walk along the Red Square in Moscow, Russia on Aug. 6, 2010. Moscow was shrouded by a dense smog that grounded flights at international airports and seeped into homes and offices, due to wildfires worsened by the city's most intense heat wave in its history. The heat wave and fires during the summer of 2010 killed over 55,000 people in Russia and decimated the Russian wheat crop, causing global food prices to spike. (AP Photo/Mikhail Metzel)

Two fundamental atmospheric flow patterns may be resonating more often due to global warmingEarth's atmosphere has two fundamental patterns. One is a series of wave-like troughs and ridges in the jet stream called planetary (or Rossby) waves, which march west-to-east at about 15 - 25 mph around the globe. The other pattern behaves more like a standing wave, with no forward motion, and is created by the unequal heating of the equatorial regions compared to the poles, modulated by the position of the continents and oceans. A number of papers have been published showing that these two patterns can interact and resonate in a way that amplifies the standing wave pattern, causing the planetary waves to freeze in their tracks for weeks, resulting in an extended period of extreme heat or flooding, depending upon where the high-amplitude part of the wave lies. But what the Potsdam Institute scientists found is that because human-caused global warming is causing the Arctic to heat up more than twice as rapidly as the rest of the planet, the two patterns are interacting more frequently during the summer. During the most recent eleven years, 2002 - 2012, there were eight Julys and Augusts that showed this unusually extreme resonance pattern (this includes the U.S. heat wave of July - August 2012.) The two previous eleven year periods, 1991 - 2001 and 1980 - 1990, had just four extreme months apiece. Global warming could certainly cause this observed increase in the resonance phenomenon, but the researchers cautioned, "The suggested physical process increases the probability of weather extremes, but additional factors certainly play a role as well, including natural variability. Also, the 32-year period studied in the project provides a good indication of the mechanism involved, yet is too short for definitive conclusions. So there's no smoking gun on the table yet--but quite telling fingerprints all over the place."

Figure 4. The northward wind speed (negative values, blue on the map, indicate southward flow) at an altitude of 300 mb in the mid-latitudes of the Northern Hemisphere during July 2011 and July 1980. July of 2011 featured an unusually intense and long-lasting heat wave in the U.S., and the normally weak and irregular waves (like observed during the relatively normal July of 1980) were replaced by a strong and regular wave pattern. Image credit: Vladimir Petoukhov.

CommentaryThe new Potsdam Institute paper gives us a mathematical description of exactly how global warming may be triggering observed fundamental changes in large-scale atmospheric flow patterns, resulting in the observed increase in unusually intense and long-lasting periods of extreme weather over the past eleven years. The paper also adds important theoretical support to the research published in 2012 by Dr. Jennifer Francis of Rutgers University, which found that the amplitude of Earth's planetary waves had increased by over 100 miles (161 km) in summer over the past decade in the Northern Hemisphere. Dr. Francis theorized that this change was connected to increased heating of the Arctic relative to the rest of the Earth, due to the observed decline in late spring Northern Hemisphere snow cover. Humans tend to think linearly--one plus one equals two. However, the atmosphere is fundamentally non-linear. What may seem to be modest changes in Earth's climate can trigger unexpected resonances that will amplify into extreme changes--cases where one plus one equals four, or eight, or sixteen. In some cases, when you rock the boat too far, it won't simply roll a bit more, it will reach a tipping point where it suddenly capsizes. Similarly, human-caused global warming is capable of pushing the climate past a tipping point where we enter a new climate regime, one far more disruptive than what we are used to.

Julys and Augusts since 1980 when quasiresonant extreme conditions were observedThe Potsdam Institute's research lists sixteen July and August periods since 1980 that have had extreme atmospheric flow patterns due to quasiresonance. These months featured severe regional heat waves and destructive floods in the Northern Hemisphere midlatitudes, detailed below. Half of these months occurred in the most recent 11-year period, 2002 - 2012. During most of these extreme months, there was not a moderate or strong La Niña or El Niño event contributing to the extremes. Summers when a La Niña or El Niño event was present are listed in parentheses, based on the Oceanic Niño Index (ONI).

July and early August 2012: Catastrophic floods in China and Japan, as well as record-breaking temperatures during heat waves in the United States and southern Europe (weak summer El Niño)

July 2011: Record heat wave in the United States, resulting in the fourth warmest July on record nationally and the driest conditions in the southern United States ever (weak summer La Niña)

July/August 2010: Russian heat wave and the Pakistan flood, with the strongest and most persistent extreme weather conditions and the highest death tolls from heat waves and floods ever for these two regions (strong summer La Niña)

July 2006: Temperatures higher than 100°F for only the second time in Britain’s history and much of Europe experiencing a serious heat wave (weak summer El Niño)

August 2004: Much of northern Europe hit by very low winter-like temperatures and sporadic snowfalls (moderate to strong summer El Niño)

July 2000: Destructive floods in northern Italy and the Tisza basin and a simultaneous heat wave in the southern United States, smashing all-time high-temperature records by that time at many sites (strong summer La Niña)

July/August 1997: Disastrous Great European Flood, which caused several deaths in central Europe, and the destroying floods in Pakistan and western United States (strong summer El Niño)

July 1994: Very strong heat wave in southern Europe, with a national temperature record of 47.2°C set in Spain (weak summer El Niño)

July 1993: Unprecedented great flood in the United States that reigned over the country from April (weak summer El Niño)

July 1989: Unusually intense and unprecedented widespread drought in the United States (weak summer La Niña)

August 1987: Severe drought in the southeastern United States (strong summer El Niño)

August 1984: Continuation of the severe heat of summer 1983, with serious drought in the United States (weak summer La Niña)

July and August 1983: Very dry conditions, severe heat, and substandard crop growth (5–35% below normal) in the Midwest United States (weak summer El Niño)

Press release issued in March 2013 by the Potsdam Institute for Climate Impact Research (PIK), "Weather extremes provoked by trapping of giant waves in the atmosphere."

In this 40-minute lecture presented in 2013 at the University of Arkansas, Dr. Jennifer Francis of Rutgers University explains the linkage between warming in the Arctic due to human-caused global warming and an observed shift in Northern Hemisphere jet stream patterns.

but to be honest iam expecting an 8.0 or greater event when and where i have no idea but its been awhile since one has occur so its about time for one to happen hopefully no where near S.cal but i never rule anything out

A great number--the majority, in fact--of the colored squares showing up on the SCEC's "Recent Earthquakes" map are spurious, and will be flushed soon. Most are system messages automatically sent when an actual shock is felt; these will usually pop up by the dozens when an area with great seismometer coverage--such as SoCal--is affected by a real quake. If in doubt, simply click on the squares for details; the spurious ones will always be led by the following disclaimer: This is a computer-generated message. This event has not yet been reviewed by a seismologist.

That is a big differance in earthquakes. 5.2 to now a 4.7. Yes I do know that it was not a 6 or 7 or god the 9. Worried about all those little quakes. Not a normal sequence for quakes in your area. Lot of aftershocks... worries me.

Funny it is weird ... and the GFS was strange too with a tiny low racing across the US and hit the atlantic where it explodes along the east coast .. but both 12Z seem funny . guess we will have a better Idea tomorrow evening ...

Quoting JustPlantIt:The original quake, (the first one), was a 5.2 according to the USGS. All of the aftershocks, etc erode the original. Again as I have said before, this needs to be fixed by the USGS as aftershocks on top of the original earthqauke make it difficult to track seismic activity.

Quoting weathermanwannabe:Hey Yall. We can crunch all the analog numbers/years, and prospective long-term models, in terms of the 2013 Atlantic H-Season all we want but the last several years have been full of surprises; large numbers of storms regardless of enso cycle, large percentage of tropical storms vs. predicted majors that never materialized, and no major landfalls in the US when steering patterns appeared favorable (last year coming to mind the the very fast westerlies kept several storms from blowing up past TS level).

Anything could happen this year is my point and it is all a wait and see...........It will be interesting fo sho to see what this year brings and whether it will also be out of the norm at any given level.

... Yeah.. that's right, I agree 100%! wait a minute... did you just say ANYTHING?! ;)